Concentrating device for telephone-transmitters.



the feeding-heed with e UNITED STATES PATENT OFFICE.

I ALFRED VON PARAVlUlNl, U! HAGEN, \YIIS'IPHALIA, (ti-IRMA NY.

PROCESS .FOR DIMIN'ISHING THE FORMATION-0F FLAWS OR BLOW-HOLES WHENCASTING BLOCKS AND OTI'LER PIECES.

To all whom it may concern:

Be it known that I, ALFRED vou PAn'm'i- CLNI, engineer, a subject. ofthe EIIIJGTOI ol' Ausi rid-Hungary, ondresident of E bcrleldcrsirnsse58, Hagen, West )halia, Germany, have invented new and use 'ul 1111rovcnients in Processes for Diminishing the ormntion of Views orBlowJ-Iolcs When (:tsting Blocks and other P ieccs, of whichtheliollowing is e specification. V

This invention relates to o rocess for diminishing the formntionof lawsor blow holes when casting blocks mid other pieces,

which is adcoinplished by cooling of the feeding-hen 'lhe object of thisprocess, which may he (preven ting it rapid called thePnrevieini-process,'is in the case of the present invention attained bycovering protecting layer,

which consists of a hottom' :tyer of n pulver ons or granular materialof a great specific weight, which exerts no influence on the castmaterial, and of aseoond layer of a combustible i'nsrterinl covering thefirst, which is A protecting, layer formed, in this wsty,'oi substencesof different kinds not onl reduces the radiation'of-heat from the-feetinc-hood, but it restores, at the some time, the lost heat by a slowcombustion of the combustible toplayer,' and acts as a weight on thenutterial forming the feet'ling-heitd, which promotes the flowing ofthe. feeding-hood nuiteriitl into the flawsor blow-holes.

As i'nsttt'lrinl for the protecting, layer, with which the surface ofthe lccd'ing'head is to he covered, there are to be'rccomlnoiulcd moreespecinlly,.on the one side, sztnd, purticw larly the soce.lledsilver-sand, and, on the other, pulverized coke. Especially with regardto the lust named mittericltherc is to he remarked tluit it produces forbetter results tluui', for instance;charcoal?" ilt reason of this"-Plmnrs to he that coke islcss conihuw tihle end. has a. much greatersp -ciiic weight.

'lhenmtermls serving to lorm the preterilng layer are preferably highlylimited hel'oro they are put on the metal.

With regard to the time or moment at which'tlie protecting layer shouldhopui on it is to he rcnmrhcd that this should iulie place its soon il-H possible ni'icr the llH HlJHPldil has been poured into the mold.eestin gand the utting on of the protectinp layer there has readyelapsed so much time Specification of Letters Patent. Application filedOctober 16, 1908. Serial No. 458,141.

ll'hetween the that a. thick cost has already been for ed in consequenceoi the cooling, it is best to uld, before putting on the inert layer, ns Xtll quantity of a deilegrating compound, sum ii. for instance, aschlorate of potassium, whereby there is reestablished the degree offluidity of the material in the feeding-hind which is requisite forsuccess. Also in such cases in which the temperature of the feeding-headis sufliciently high so as not to require a special heating by adelhigrating compound, the protecting-layer used according to thisinvention may be applied in combination with an addition of adeihwrotinp compound, although in this case t to use of e deliagrntingcompound is not necessary for success.

The process is preferably carried out as follows: A crucible holding 10liters or more is hell' filled with fine sand, for instance socnlledsilve1'send, and finely ground coke, in a. manner that the coke lies atthe bottom and the sand at the top. The crucible thus filled is highlyheated in e heating-stove. If new a block is cast or any other piece,the'whole contents of the crucible are, shortly before the cesting isfinished, or, ii this isiinpossible, immediately after the custin isfinished, )ourcd into [the chill-mold. 'fiiere is therel'ore lying onthe surface of the l'luid metal first the highly heated sand and on topof that the glowing coke. 'lhc pr )tecting layer of sand and coke actsits a. hen store'r or reblock is kept in a'liuid state during the wholeperiod during which flows or blow-holes are formed, so that fluid steelcan continuously flow into these [laws or blow-holes. As the weight ofthe protecting layer is considerable, it exerts a ressure which,considerihgthe liuid state oi the metal, may be called great,whcrebythere is cfi'ectcd at nearly uniform sinking, down oi the wholeupper part of the diminution of the ionnetiqn ol' flows or blowholi-s.What is'oi' a. pn ticularly practical importance with the new process isthat no alter-cast ingot all is required, as the feedinghi-ud is lttpiin u. lluid state to such an extent that it is :it once sullicicnt forgiving oil the [luid material required for filling the blowholos orHaws.

What l claim as my invention and desire to secure by United Statesliclivrs Patent l l 1s:-- l l. 'lheniethod ol' dimiui thing the formataincr, by which the upper end of the steelblock. This fact greatlycontributes to the llU tion of flaws or blow-holes in the casting ofterial in a state of division which is substanl tlally inert wlthrelation to the metal to be east and with a top layer of a combustiblesubstance likewise in state of division.

2. The me-thodof diminishing the formation of flows or blow-holes in therusting ol' blocks and other pieces, which eonsists in covering thesurface of the leedin head with a bottom lnyer of sand and wilh :1 toplayer of pulverized (woke.

'3. The method of dinnnishing;- the l'ormntion of flaws of blow-holes inthe Uitfitlllt: ol' blocks and other pieees, whirl! ronsists in heatingpulverized combustible material and ulverlzed inoolnbnstible nmterinlwhich is inert with relation to the metal to be cast tovessel and inthereafter tilting over the vessel so as to bring its contents on thefeeding head with the layer of inert material downside and thecombustible snbstanee topside.

4. Themethod of diminishing the formation of Hans or blow-holes in thecasting of blocks and other pieces, which consists in putting onthe'leeding head a small quantity of a del1u, n'utin; mixture and inthereol'ter eovering the surl'aee ol' the feeding head with :1 bottomlayer of solid ineombnstible Inaterial in it state of division \shioh issubstange-ther in a suitable vessel,the combustible substance forming abottom layer and the 111- combustible substamqe a top layer 111 sandtially inert nith relation to the metal to be east and with tt top layerolit combustible substance likewise in state of division.

in testimony, that 1 claim the foregoing its my invention, l have signedmy name in presence of two witnesses, this 30th day of September 1908'.

ALFRED VON PARAVIUINI. IL. 8.] Witnesses:

OTTO Komo, WM. WAsnINo'mx BRUNSWICK.

